Fennel outperforms ajwain and anise in saline environment: physiological response mechanisms in germinating seeds and mature plants

Abstract

The potential of different medicinal species as alternative crops for saline conditions needs to be explored. Comparative physiological responses of germinating seeds and mature plants of three genotypes of anise (Pimpinella anisum L.), fennel (Foeniculum vulgare Mill.), and ajwain (Trachyspermum ammi L.) to salt were studied in a 2-year field experiment using 0 and 100 mcM, and a laboratory experiment using 0, 25, 50, 75, 100, and 125 mM NaCl. Catalase and ascorbate peroxidase activities increased in the salt-stricken plants of all genotypes, but only peroxidase activity of the salt-treated plants of anise genotypes and two of the fennel genotypes increased under field conditions. Chlorophyll and K+ concentrations of all genotypes decreased, but proline and Na+ concentrations and Na+/K+ increased under saline conditions. Dry mass, grain yield, and essential oil yield decreased in the salt-exposed plants across all genotypes and species. Germination, root, and shoot length were suppressed upon exposure to saline water. Despite the increasing trend of the proline and polyphenol concentrations and catalase and peroxidases activities, ascorbate peroxidase activity of germinating seeds decreased with an increase in NaCl concentration. Smaller adverse effects of salt on fennel germination attributes, grain and essential oil yields were evident. Moreover, greater activities of antioxidative enzymes and maintained Na+ and Na+/K+ of salt-stricken fennel plants were observed. These findings indicate that germinating seeds and mature plants of fennel have a greater ability to withstand salinity than the other examined species.

Investigating foliar application of bulk and nanoparticles titanium dioxide on fennel productivity to mitigate the negative effects of saline irrigation water

“…This research found that fennel plants exposed to SALIW experienced substantial reductions in plant height, fresh and dry weights and fruit yield; it might be as a result of SALIW, a source of toxic ions that raise the osmotic pressure of soil solution [ 47 ]; therefore, plant roots are unable to extract water from the surrounding soil, and plant exposure to drought causes a drop in turgor, which causes a decrease in plant cell development, which is followed by growth inhibition [ 48 ]. Fennel, which is known to be susceptible to abiotic stress factors [ 21 ], may be made to tolerate SALIW stress better by applying Ti forms to its leaves. Prior research has demonstrated beneficial effects of TiO 2 form treatments (as foliar a spray) on the balance and absorption of critical macro and micronutrients; this causes chlorophyll and protein levels to rise, resulting in an increase of growth, dry matter content and yield under SALIW conditions [ 23 ].…”

“…The effects of SALIW vary depending on plant species [ 13 , 14 ]. SALIW with sodium chloride (NaCl) in fennel leads to decreased plant growth, fresh and fruit yield, relative water content, EO, lipids, oleic and linoleic acids, POTSP, potassium (K), calcium (Ca) and magnesium (Mg); while, proline (PROL), CARB, TPHEN, malondialdehyde (MDA), hydrogen peroxide (H 2 O 2 ), antioxidant enzymes activity (AOEA), total soluble solids (TSS), sodium (Na), major components of EO (limonene, fenchone, estragol, trans -anethol) and palmitic acid increased [ 15 – 21 ].…”

“…Unfortunately, those areas have only groundwater that contains salts, especially NaCl. Previous research has shown that fennel plant can tolerate small amounts of SALIW, but that excessive salt concentration, especially those containing NaCl can injure fennel plant; prior research has demonstrated that fennel plants can withstand saline levels of up to 1.6 dS m −1 ; above that point, the plant's output and active ingredient concentration start to decline [ 21 ]. Consequently, this research aimed to lessen the negative impacts of SALIW on fennel plants by foliar spraying fennel plants with Ti forms (TiO 2 or TiO 2 NP) to help them become tolerant to SALIW; this research has never been done previously, particularly in Egypt.…”

Synergistic effects of calcium and melatonin on physiological and phytochemical attributes of Dracocephalum kotschyi genotypes under salinity stress

“…Enhancement of the secondary metabolites of TPC and TFC type is known to be common among different plant species and expressed in response to different stresses. Moreover, genotypic differences in the pattern and extent of increase in antioxidative defense (Dionisio‐Sese & Tobita, 1998; Nouripour‐Sisakht et al, 2022), particularly antioxidant compounds (Gharibi et al, 2019), are expected. Among the examined genotypes, Fereydunshahr had a greater TPC concentration than the other genotypes, and Bojnord had a greater TFC concentration than the remaining genotypes (Table 5).…”

“…Therefore, the total essential oil concentration of the leaf samples was consistent with those of histochemical evaluation of the glandular trichomes. An increase in the essential oils concentration is common to different environmental stresses and also among different medicinal species (Nouripour-Sisakht et al, 2022). Moreover, the extent of the increase in essential oils concentration increases with the intensity and duration of the environmental stresses (Charles et al, 1990).…”